Draft gears for railway cars



March 13, 1956 H. E. TUCKER 2,738,078

DRAFT GEARS F OR RAILWAY CARS Filed Sept. 7, 1951 2 Sheets-Sheel'I 2 iQ-2 M gg-J V/M7////////////// United States Patenti-#e A Thisinvention' rclatesto draft gears for railway cars, andi has'forf its" principal Vobjecttoprovide'a relatively soft' cushioii 4iunit" of@ short'travel"'and""low `capacity". actingA iniliuffand in #diaft'j land a relatively liard' long travelcnsli-v ion'ing unitlofhigl capacity also' actingv` in bulfoily 'and' in series 'with the relatively soft" cushioning" unit."

@ther objects; and" advantages of the invention will 1 appear" as the"descriptionA is read in connection with then-accompanyingedrawings;in'whichz Fig; 1l isf a' horiiontal section' through the draft gear Eiga 2tis aldiagram'givingv comparative'icurvesof the two cushioningiunits'fand a combination oflthe two; and'F YFigSissa perspective'view indicating liowih'e resilient" elements forifspringl ele1i'1ent`s`are'v made Avup.

Initlie-'drawing'sgffllandlllindicate with draft lugs 12 and 13 which together-delinea con# ventional draft gear pocket. Associated with ,those parts is a coupler shank"` 11F-and adi-aft yokelS connected to the coupler. shank in .Iany= suitable' way.

The. draft, gear includes a housing ,16. divided byfa-gpartitidt'i` 17".into a generally rectangular. rear. chamber .18 (Fiig.;2) .for the. low capacity cushioning-unit, andzagenerllyj.hexagonal"frontv chamber .19y .(.Fige 3) for the*l high' capacity cushioning unit'.`

Tlie soft,` low capacity `or real' cushioning ;-.unit;. isi` made`- up of"resilient' elements or spring-A ielements,", genera'lly indicatdf by 20', alternating. with. spacerssyAss shQwn'tinFig; 5; each elmentis made upfof a plat'ewZvlf of relatively incompressible..v material ',(preferab'lyfA steel i 3266i" S E? 1.010 is"satisfa'ctry)" provided with-irows'i; of `ali'gnedj spaced openings '22,` rubber bars or mats 23' overlying the rows of openings on each side of theV plateV are connected by plugs 24. The bars and plugs are of material such as rubber composition, of suitable durometer hardness, for example 58 to 62. The connection between the bars and the plugs, or one bar and the plugs, `is effected by vulcanizing, which may, or may not, also make the bars fastV to the steel plates.

In making up the soft, low capacity cushioning unit in this embodiment, three resilient or rubber elements, including plates 21 and rubber blocks 23, alternate with steel spacer plates 25, the group or pack having an overall length in excess of the length of the chamber 18 approximately one inch, thus providing a one-inch soft travel low capacity cushion for buff and draft shocks. In use, it is assembled between the partition 17 and a back follower plate 26.

The high capacity long travel cushioning unit, or front unit, is preferably substantially as disclosed in the patent to Cardwell, 2,496,442 of February 7, 1950. However, in this instance the inner and outer coil springs are shown replaced by a cushioning element composed of five main rubber springs, generally indicated by 27 in Fig. l, alternating with spacers 28. Each rubber spring is made up of a plate 32 provided on each side with concentric rubbei spacedsillsi equipped i rings7 29 i-connected .b y,r blocks 30.- through.. /openings..;31f formedin.the.plate.32;

Theremainder.` of Athefrictiony drafti `geari-disclosedfrini' theA said'. Cardwellf patenti-is not 1 here i described iin detail, but Athe..disulosurednthat patent. isincluded by7 reference: in theinterestcf brevity.`

The rear follower 26 has a hollow boss 33 which re` ceives the.-headed.end42ofrthe bolt 40. which'.v passes through .the friction .draftgearand sei-.ves` to 'retain thetunits` in,.assemb1e`d relatiomas shownrin Fig; 1.

A.,:front..followert.37. is disposed@ betweenV the-coupler.`

.shank `142 and-the.: friction.. cushioning unit and transf'v mits..v buff. loads` therebetween. The vfront follower isv limited .in ,itstforward travel i byabutmentv with.` therfront' draftlugsl;`

.In operation, the soft.flow capacity' rubber cushioning e unit. provides.. one inch. travel in all ,important draft-lv shocks.. Theactionislsoft andeasy and .hast plentyy of.

capacityfand travel. That softlow capacity. cushioning-,uuitvalso providesoneinch travelontherubber in buff. Any light .bungshocks willA probably, be. taken careof. mostly by. the-l rubber,

though. undoubtedly at it` reaches Ythe endfof: its,-.co1r1preszW sionfthefriction will'comeinplay. The two-cushioning unitsactihgtogether providefullthree: inches of travel-inl v bulli,J andwliile .light buffshocks. are taken principally, by f the softllow capacity unit there.is.fnecessarily a blending,

andas tlielow capacity unit reachesthe ycapacity of limited- 4 trav'eftlie friction draft .gear cornes into.full .play for two inches, cr-approximately twoinches, of capacity` Y Generally speaking,1 tlie liigh .capacity cushioning, unit.

capacity o'r exceedingtlie capacity of the soft-,.low cushioning unit. `When that occursthe. friction offthehighcapacity unit 'will' comel'intolplay .and .take carek of .the shock.- l

Referrfii'i'gjt'oFig, `4, the. results. are graphically shown..

vTlie `clir'a'racteris'tic(curve of' the YCardwell friction gear` shownatapproaclies a straightline. wlienplottedlwitli` inches ofltravellas abscissa and load'sas ordinates. The

characteristiccurve of rthe low capacity cushioningunit inf` dicate'd'atiSljis quite a. long curve. The. combinationv of thetwois indic'atedbyV the curve `52 from which itwill.

hard an l""soft" are`et`nployed to describe the cushioning units they should be understood to refer to the cushioning units as a whole and not necessarily to the individual elements thereof. The characteristic load-decction curve for a relatively hard cushioning unit, of course, shows that for a given increment of load there results only a small deflection, whereas the characteristic loaddeection curve for a relatively soft cushioning unit for a similar increment of load would produce a substantially greater deflection.

I claim: i

1. In a draft gear for a railway car having a draft gear pocket, a draft yoke, followers movable by the yoke, and spaced stops against which the followers normally rest, a housing mounted in the draft pocket for longitudinal movement therein between one of said stops and one of said followers, said housing normally occupying a position with one end thereof abutting said one stop and the opposite end thereof spaced from said one follower, a

partition wall in said housing dividing it into two charn-V Pajtented Mar. 13, 195.6

and the other of said followers, said one follower being movable by said draft yoke away from its associated stop to cause said rst mentioned cushioning unit to act in draft, said housing, during such movement of said one l follower, being held against movement by the stop which it normally abuts, whereby said friction cushioning unit is prevented from acting in draft, said other follower being movable by said draft yoke away from its associated stop to cause both of said cushioning units to cooperatively act in buff.

2. In a draft gear for a railway car having a draft gear pocket, a draft yoke, followers movable by the yoke, and spaced stops against which the followers normally rest, a housing mounted in the draft pocket for longitudinal movement therein between one of said stops and one of said followers, said housing normally occupying a position with one end thereof abutting said one stop and the opposite end thereof spaced from said one follower, a partition wall in said housing dividing it into two chambers of different lengths and cross-sections, a short travel cushioning unit in the shorter chamber between said partition wall and said one follower, said cushioning unit including a series of rubber blocks alternating with relatively incompressible plates, a friction cushioning unit in the second chamber between said partition wall and the other of said followers, said short travel cushioning unit being softer than said friction cushioning unit, said one follower being movable by said draft yoke away from its associated stop to cause said rst mentioned cushioning unit to act in draft, said housing, during such movement of said one follower, being held against movement by the stop which it normally abuts, whereby said friction cushioning unit is prevented from acting in draft, said other follower being movable by said draft yoke away from its associated stop to cause both of said cushioning units to coopera: tively act in buff.

3. In a draft gear for mounting in a draft gear pocket of a railway car, said pocket having front and rear stop lugs, and adapted to be actuated by a coupler yoke encircling the gear, a housing mounted in the pocket for longitudinal movement therein, a partition wall in said housing dividing it into two chambers of different lengths, a rear cushioning unit in the chamber of shorter length and having one end abutting said partition wall, a rear follower abutting the opposite end of said cushioning unit, said rear follower and housing having cooperating portions for limiting relative movement of said follower toward said partition wall, and said portions being in longitudinally spaced relation whereby said follower may move toward said partition wall to cause said cushioning unit to act in draft, a front cushioning unit in the chambers of greater length and having one end thereof abutting said partition wall, a front follower abutting the opposite end of said front cushioning unit, said front follower and said housing being movable toward said rear follower to cause both of said cushioning units to act in buff, said housing normally abutting against said front stops to prevent movement thereof when the gear is acting in draft whereby said front cushioning unit is prevented from acting in draft.

4. The invention recited in claim 3, wherein said rear cushioning unit is softer than said front cushioning unit.

5. In a draft gear for mounting in a draft gear pocket of a railway car, said pocket having front and rear stop lugs, and adapted to be actuated by a coupler yoke encircling the gear, a housing mounted in the pocket for longitudinal movement therein, a partition wall in said housing dividing it into front and rear chambers, a rear cushioning unit in said rear chamber having one end thereof abutting said partition wall, a rear follower abutting the opposite end of said cushioning unit, said follower and housing having cooperating portions for limiting relative movement of said rear follower toward said partition wall and said portions normally being in longitudinally spaced relation whereby said follower may move toward said partition wall to cause said rear cushioning unit to act in draft, a front cushioning unit in said front chamber having one end abutting said partition wall, and a front follower abutting the opposite end of said front cushioning unit, said front follower and said housing being movable toward said rear follower to cause both of said cushioning units to act in buff, said housing normally abutting against said front stops to prevent movement thereof when the gear is acting in draft whereby said front cushioning unit is prevented from acting in draft.

UNITED STATES PATENTS References Cited inthe file of this patent 776,390 Gallagher, lr Nov. 29, 1904 911,902 OConnor Feb. 9, 1909 922,619 OConnor May 25, 1909 1,096,120 OConnor May 12, 1914 1,113,916 Spencer Oct. 13, 1914 1,123,356 OConnor Jan. 5, 1915 1,136,029 Miner Apr. 20, 1915 1,702,675 Ventura Feb. 19, 1929 1,807,132 Pappas et al. May 26, y1931 1,853,857 Glascodine et al Apr. 12, 1932 1,860,540 Haseltine May 31, 1932 

